api: Allow setz to strictly lower an occulter

This will be useful for various things, including in particular
recovering from things stuck under occulters, and making the UI "b"
work properly.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/daemon/api.rs b/daemon/api.rs
index 6b62f955e29d2b98c26164a4e516b4f37beb2227..db4636a20cd0ac64ca3153130269ed753cd86fe2 100644 (file)
--- a/daemon/api.rs
+++ b/daemon/api.rs
@@ -450,7 +450,9 @@ api_route!{
   fn op(&self, a: ApiPieceOpArgs) -> PieceUpdate {
     let ApiPieceOpArgs { gs,piece, .. } = a;
     let gpc = gs.pieces.byid_mut(piece).unwrap();
-    if gpc.occult.is_active() { throw!(OE::Occultation) }
+    if gpc.occult.is_active() {
+      if self.z >= gpc.zlevel.z { throw!(OE::Occultation) }
+    }
     gpc.zlevel = ZLevel { z: self.z.clone(), zg: gs.gen };
     let update = PieceUpdateOp::SetZLevel(());
     (WhatResponseToClientOp::Predictable,